Fiber-Optics Quench Detection Schemes in HTS Cables for Fusion Magnets
G. Colombo, Sayyed Ashkan Adibi, Marco Breschi, M. Caponero, A. Castaldo, G. Celentano, A. della Corte, Marcello Marchetti, Andrea Masi, C. Mazzotta, L. Muzzi, Andrea Polimadei, Laura Savoldi, Antonio Trotta, Fabio Zanon, G. De Marzi
Abstract
In this paper, we report the results from two test campaigns conducted to evaluate the feasibility of implementing a commercially available optical fiber-based distributed sensing technology for quench detection purposes. We successfully characterized the temperature response and sensitivity achievable by this technique when using a bare single mode fiber within a cryogen free cooling system operating in the temperature range from 4 K to 300 K. A fiber was also incorporated into a sample featuring an HTS stack mounted onto an extruded Aluminum slotted-core cable. Quench-like events were triggered by locally lowering the critical current using the magnetic field produced by a set of permanent magnets placed near the center of the stack. The experiments were carried out at 77 K by cooling the sample through the central channel of the Aluminum core with a forced flow of liquid nitrogen. The test results indicate the viability of this technology as a suitable alternative for Quench Detection in long-length HTS cables and motivate further work to develop distributed sensing systems able to work in the conditions foreseen for HTS fusion coils.